Commit | Line | Data |
---|---|---|
25985edc | 1 | /* Inject a hwpoison memory failure on a arbitrary pfn */ |
cae681fc AK |
2 | #include <linux/module.h> |
3 | #include <linux/debugfs.h> | |
4 | #include <linux/kernel.h> | |
5 | #include <linux/mm.h> | |
31d3d348 WF |
6 | #include <linux/swap.h> |
7 | #include <linux/pagemap.h> | |
43131e14 | 8 | #include <linux/hugetlb.h> |
7c116f2b | 9 | #include "internal.h" |
cae681fc | 10 | |
847ce401 | 11 | static struct dentry *hwpoison_dir; |
cae681fc AK |
12 | |
13 | static int hwpoison_inject(void *data, u64 val) | |
14 | { | |
31d3d348 WF |
15 | unsigned long pfn = val; |
16 | struct page *p; | |
43131e14 | 17 | struct page *hpage; |
31d3d348 WF |
18 | int err; |
19 | ||
cae681fc AK |
20 | if (!capable(CAP_SYS_ADMIN)) |
21 | return -EPERM; | |
31d3d348 WF |
22 | |
23 | if (!pfn_valid(pfn)) | |
24 | return -ENXIO; | |
25 | ||
26 | p = pfn_to_page(pfn); | |
43131e14 | 27 | hpage = compound_head(p); |
31d3d348 WF |
28 | /* |
29 | * This implies unable to support free buddy pages. | |
30 | */ | |
43131e14 | 31 | if (!get_page_unless_zero(hpage)) |
31d3d348 WF |
32 | return 0; |
33 | ||
fb31ba30 WL |
34 | if (!hwpoison_filter_enable) |
35 | goto inject; | |
36 | ||
43131e14 | 37 | if (!PageLRU(p) && !PageHuge(p)) |
facb6011 | 38 | shake_page(p, 0); |
31d3d348 WF |
39 | /* |
40 | * This implies unable to support non-LRU pages. | |
41 | */ | |
43131e14 | 42 | if (!PageLRU(p) && !PageHuge(p)) |
7ea434a4 | 43 | goto put_out; |
31d3d348 WF |
44 | |
45 | /* | |
46 | * do a racy check with elevated page count, to make sure PG_hwpoison | |
47 | * will only be set for the targeted owner (or on a free page). | |
48 | * We temporarily take page lock for try_get_mem_cgroup_from_page(). | |
cd42f4a3 | 49 | * memory_failure() will redo the check reliably inside page lock. |
31d3d348 | 50 | */ |
43131e14 NH |
51 | lock_page(hpage); |
52 | err = hwpoison_filter(hpage); | |
53 | unlock_page(hpage); | |
31d3d348 | 54 | if (err) |
7ea434a4 | 55 | goto put_out; |
31d3d348 | 56 | |
0d57eb8d | 57 | inject: |
4883e997 | 58 | pr_info("Injecting memory failure at pfn %#lx\n", pfn); |
cd42f4a3 | 59 | return memory_failure(pfn, 18, MF_COUNT_INCREASED); |
7ea434a4 NH |
60 | put_out: |
61 | put_page(hpage); | |
62 | return 0; | |
cae681fc AK |
63 | } |
64 | ||
847ce401 WF |
65 | static int hwpoison_unpoison(void *data, u64 val) |
66 | { | |
67 | if (!capable(CAP_SYS_ADMIN)) | |
68 | return -EPERM; | |
69 | ||
70 | return unpoison_memory(val); | |
71 | } | |
72 | ||
cae681fc | 73 | DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n"); |
847ce401 | 74 | DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n"); |
cae681fc AK |
75 | |
76 | static void pfn_inject_exit(void) | |
77 | { | |
c2ea2181 | 78 | debugfs_remove_recursive(hwpoison_dir); |
cae681fc AK |
79 | } |
80 | ||
81 | static int pfn_inject_init(void) | |
82 | { | |
847ce401 WF |
83 | struct dentry *dentry; |
84 | ||
cae681fc AK |
85 | hwpoison_dir = debugfs_create_dir("hwpoison", NULL); |
86 | if (hwpoison_dir == NULL) | |
87 | return -ENOMEM; | |
847ce401 WF |
88 | |
89 | /* | |
90 | * Note that the below poison/unpoison interfaces do not involve | |
91 | * hardware status change, hence do not require hardware support. | |
92 | * They are mainly for testing hwpoison in software level. | |
93 | */ | |
2d1e8b3f | 94 | dentry = debugfs_create_file("corrupt-pfn", 0200, hwpoison_dir, |
cae681fc | 95 | NULL, &hwpoison_fops); |
847ce401 WF |
96 | if (!dentry) |
97 | goto fail; | |
98 | ||
2d1e8b3f | 99 | dentry = debugfs_create_file("unpoison-pfn", 0200, hwpoison_dir, |
847ce401 WF |
100 | NULL, &unpoison_fops); |
101 | if (!dentry) | |
102 | goto fail; | |
103 | ||
1bfe5feb HL |
104 | dentry = debugfs_create_u32("corrupt-filter-enable", 0600, |
105 | hwpoison_dir, &hwpoison_filter_enable); | |
106 | if (!dentry) | |
107 | goto fail; | |
108 | ||
7c116f2b WF |
109 | dentry = debugfs_create_u32("corrupt-filter-dev-major", 0600, |
110 | hwpoison_dir, &hwpoison_filter_dev_major); | |
111 | if (!dentry) | |
112 | goto fail; | |
113 | ||
114 | dentry = debugfs_create_u32("corrupt-filter-dev-minor", 0600, | |
115 | hwpoison_dir, &hwpoison_filter_dev_minor); | |
116 | if (!dentry) | |
117 | goto fail; | |
118 | ||
478c5ffc WF |
119 | dentry = debugfs_create_u64("corrupt-filter-flags-mask", 0600, |
120 | hwpoison_dir, &hwpoison_filter_flags_mask); | |
121 | if (!dentry) | |
122 | goto fail; | |
123 | ||
124 | dentry = debugfs_create_u64("corrupt-filter-flags-value", 0600, | |
125 | hwpoison_dir, &hwpoison_filter_flags_value); | |
126 | if (!dentry) | |
127 | goto fail; | |
128 | ||
c255a458 | 129 | #ifdef CONFIG_MEMCG_SWAP |
4fd466eb AK |
130 | dentry = debugfs_create_u64("corrupt-filter-memcg", 0600, |
131 | hwpoison_dir, &hwpoison_filter_memcg); | |
132 | if (!dentry) | |
133 | goto fail; | |
134 | #endif | |
135 | ||
cae681fc | 136 | return 0; |
847ce401 WF |
137 | fail: |
138 | pfn_inject_exit(); | |
139 | return -ENOMEM; | |
cae681fc AK |
140 | } |
141 | ||
142 | module_init(pfn_inject_init); | |
143 | module_exit(pfn_inject_exit); | |
144 | MODULE_LICENSE("GPL"); |